<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    *{margin: 0;padding: 0}
    input{
        border: 1px solid #333;
        width: 100px;
        height: 40px;
    }
    .btn{
        width:102px;
        height:42px;
    }
     /* input是按钮的形态下,给border,padding不会改变它的width,height */
    </style>
</head>
<body>
     <!-- 输入框和按钮的区别 -->
     <input type="text"> <br>
     <input type="submit" class="btn">
     <!-- <button type="submit">提交</button> -->
</body>
</html>